Staging is part of the diagnosis process. It tells you how advanced the melanoma is or whether it has spread. Staging also helps your doctor decide how to move forward with treatment and follow-up care.
Your doctor will give you a physical exam and review the results of your diagnostic and imaging tests. Then they will decide the stage of the cancer. They may adjust the stage if you have surgery or more tests.
There are 5 stages of melanoma, from 0 to 4. The lower the number, the less the cancer has spread. We also break down some stages even more, into stages A, B, C, and D.
Invasive melanoma is cancer that can spread to other areas of the body. Melanoma is divided into stages based on the thickness of the primary tumor and other features. The thickness of a tumor is the most important risk factor. The thicker the tumor, the more likely it will spread.
Breslow depth is the tumor’s thickness. It measures how deep below the surface of the skin the melanoma cells have reached. The thinner the melanoma, the better the chance for a cure. We measure tumors in millimeters.
Staging also is based on whether the skin is broken.
Ulceration means there is broken skin covering the melanoma. This break can be so small it can only be seen under a microscope. Ulceration is important for staging. A melanoma with ulceration is higher risk than the same thickness melanoma without ulceration.
What is Stage 0 Melanoma?
The scale starts at stage 0 melanoma. This is melanoma in the thin outer layer of the skin. It is not invasive and will not spread to other parts of the body. This often is called melanoma in situ.
What is Stage 1 Melanoma?
Melanoma at stage 1 is invasive. It has grown below the thin outer layer of the skin to the next layer of skin. It has not spread to lymph nodes.
Stage I melanoma includes all melanomas that are in an early stage. Staging is based on the tumor’s thickness and whether the skin is broken (ulcerated).
What is melanoma stage 1A and stage 1B?
Melanoma is stage 1A when:
- The tumor’s Breslow depth is 1 millimeter or less.
Melanoma is stage IB when:
- The tumor’s Breslow depth is 1.1 to 2 millimeters, without ulceration.
What is Stage 2 Melanoma?
Melanoma at stage 2 is invasive. It has grown below the thin outer layer of the skin to the next layer of skin. It has not spread to lymph nodes.
Stage 2 melanoma also is broken down into stages 2A, 2B, and 2C. The stage is based on the melanoma’s thickness and whether or not there is ulceration (broken skin).
What is melanoma stage 2A, stage 2B, and stage 2C?
Melanoma is stage 2A when:
- The tumor’s Breslow depth is 1.1 to 2 millimeters, with ulceration.
- The tumor’s Breslow depth is 2.1 to 4 millimeters, without ulceration.
Melanoma is stage 2B when:
- The tumor’s Breslow depth is 2.1 to 4 millimeters thick, with ulceration.
- The tumor’s Breslow depth is more than 4 millimeters, without ulceration.
Melanoma is stage 2C when:
- The tumor’s Breslow depth is more than 4 millimeters, with ulceration.
What is Stage 3 Melanoma?
Stage 3 melanoma most often describes cancer that has metastasized (spread) to nearby lymph nodes.
It can also mean melanoma that has spread beyond the primary tumor within the skin. It has not spread to the nearest lymph nodes.
Satellite melanoma is stage 3 cancer that has spread less than 2 centimeters from the primary tumor. In-transit melanoma is stage 3 cancer that has spread more than 2 centimeters from the primary melanoma. Neither has reached lymph nodes. The treatment is the same for both types.
Stage 3 melanoma is also grouped into stages 3A, 3B, 3C, and 3D. Staging is based on the melanoma’s growth and how far it’s spread.
What is melanoma stage 3A, stage 3B, stage 3C, and stage 3D?
Melanoma is stage 3A when:
- The tumor is so small it only can be seen with a microscope. It has spread to 1 to 3 nearby lymph nodes, but not to other areas.
Melanoma is stage 3B when:
Stage 3B melanomas vary in size, location, and whether they have metastasized (spread). They’re stage 3B when they fit into one of these categories.
- Either we can’t see the primary tumor or don’t know where it started. Either it’s spread to 1 nearby lymph node, or, there’s satellite melanoma, in-transit melanoma, or both.
- The tumor’s Breslow depth is 1 millimeter or less (with ulceration), or 2 millimeters or less (without ulceration). It’s either spread to 1 to 3 nearby lymph nodes, or, there’s satellite melanoma, in-transit melanoma, or both.
- The tumor’s Breslow depth is 1.1 to 2 millimeters (with ulceration) or 2.1 to 4 millimeters (without ulceration). As well, either it’s in 1 to 3 nearby lymph nodes, or, there’s satellite melanoma, in-transit melanoma, or both.
Melanoma is stage 3C when:
Stage 3C melanomas range in size and location, and whether they have spread. They are stage 3C when they fit into one of these categories.
- Either we can’t see the primary tumor or don’t know where it started. The cancer has spread to 2 or 3 lymph nodes.
- The tumor’s Breslow depth is under 2 millimeters (with or without ulceration), or not more than 4 millimeters (without ulceration). As well, either:
- Cancer is in 1 lymph node. There are satellite tumors, in-transit tumors, or both. They can be on or under the skin.
- Or, cancer is in 4 or more lymph nodes, or in lymph nodes that are matted (joined) together.
- Or, it’s in 2 or more lymph nodes, in lymph nodes that are matted together, or both. There are satellite tumors, in-transit tumors, or both. They can be on or under the skin.
- The tumor’s Breslow depth is 2.1 millimeters but under 4 millimeters (with ulceration), or over 4 millimeters (without ulceration). There’s cancer in 4 or more lymph nodes, in lymph nodes that are matted together, or both. There are satellite tumors, in-transit tumors, or both. They can be on or under the skin.
- The tumor’s Breslow depth is more than 4 millimeters (with ulceration). As well, either:
- There’s cancer in 1 or more lymph nodes.
- Or, there are satellite tumors, in-transit tumors, or both. They can be on or under the skin.
Melanoma is stage 3D when:
- The tumor’s Breslow depth is more than 4 millimeters (with ulceration). As well, either:
- There’s cancer in at least 4 lymph nodes.
- Or, there’s cancer in lymph nodes that are matted together.
- Or, at least 2 lymph nodes have satellite tumors, in-transit tumors, or both.
What is Stage 4 Metastatic Melanoma?
Stage 4 melanoma has metastasized (spread) farther from the primary site. It’s beyond the area of nearby lymph nodes. It can be in areas such as the liver, lungs, brain, bone, or gastrointestinal tract.
Melanoma can be stage 4 when it’s first diagnosed. Stage 4 melanoma can also be recurrent melanoma. Recurrent means the melanoma has come back after treatment. The cancer can come back where it first started, in the lymph nodes, or in a distant area.